In recent years, there has been an increasing use of compact, pocket-size electronic personal organizers that store personal scheduling information such as appointments, tasks, phone numbers, flight schedules, alarms, birthdays, and anniversaries. Some of the more common electronic organizers are akin to handheld calculators. They have a full input keyboard with both numeric keys and alphabet keys, as well as special function keys. The organizers also have a liquid crystal display (LCD) which often displays full sentences and rudimentary graphics.
Pocket-size personal organizers prove most useful to busy individuals who are frequently traveling or always on the move from one meeting to the next appointment. Unfortunately, due to their hectic schedules, these individuals are the people most likely to forget their personal organizers during the frantic rush to gather documents, files, laptops, cellular phones, and travel tickets before heading off to the airport or train depot. It would be desirable to reduce the number of electronic devices that these individuals need to remember for each outing.
Electronic watches have evolved to the point that they can function as personal organizers. Like the pocket-size devices described above, such watches can be programmed with certain key appointments, tasks, phone numbers, flight schedules, alarms, birthdays, and anniversaries. Since watches are part of everyday fashion attire, they are more convenient to carry and less likely to be forgotten by busy people. However, it is much more difficult to enter data into a watch than it is to enter the same data into a pocket-size personal organizer. This difficulty is due in large part to the limited number of input buttons and display characters available on reasonably-sized watches. Most watches are limited to having only three or four input buttons. A wearer programs a watch by depressing one or more buttons several times to cycle through various menu options. Once an option is selected, the user depresses another button or buttons to input the desired information. These input techniques are inconvenient and difficult to remember. Such techniques are particularly inconvenient when a wearer wishes to enter an entire month's schedule. Although watches have been made with larger numbers of input keys, such watches are usually much too large for comfort, and tend to be particularly unattractive.
Apart from personal organizers, it is common for many people to maintain appointment calendars and task lists on their personal computers. One example time management software is Microsoft's.RTM. Schedule.TM. for Windows.RTM. which maintains daily appointment schedules, to-do lists, personal notes, and calendar planning. This information is often a duplicate of that maintained on the portable personal organizer.
Timex Corporation of Middlebury, Conn., has recently introduced the Timex.RTM. Data-Link.TM. watch. This watch utilizes new technology for transferring information from a personal computer to a watch. This system is more fully disclosed and described in U.S. patent application Ser. No. 08/155,326 filed Oct. 22, 1993, now U.S. Pat. No. 5,488,571, in the names of Jacobs and Insero, and assigned to Timex Corporation. The watch case has an optical sensor which is connected to a digital serial receiver, better known as a UART (universal asynchronous receiver/transmitter), which is incorporated into an integrated circuit controlling the time keeping functions of the watch. The watch's optical sensor and UART expect to receive a serial bit transmission in the form of light pulses at a fixed bit rate. A pulse represents a binary `0` bit, and the absence of a pulse represents a binary `1` bit.
The CRT (cathode ray tube) or other scanned-pixel display of a personal computer is used to provide light pulses to the watch. Although it appears to a human viewer that all pixels of a CRT are illuminated simultaneously, the pixels are actually illuminated individually, one at a time, by an electron beam which sequentially scans each row or raster line of pixels beginning with the top raster line and ending with the bottom raster line. It is this characteristic of a CRT and of other frame-scanning display devices which is utilized to transmit serial data to the Data-Link.TM. watch.
To transtar data to the watch, the watch is held near and facing the CRT. The computer is programmed to display a sequence of display frames in which spaced data transmission raster lines represent individual bits of data. Lines are illuminated or not illuminated, depending on whether they represent binary `0` bits or binary `1` bits. Each line appears as a continuous pulse of a finite duration to the receiving watch. The watch recognizes an illuminated line as a binary `0` bit. It recognizes a non-illuminated line as a binary `1` bit. Generally, ten bits are transmitted in a single CRT display frame: eight data bits, a start bit, and a stop bit. As used herein, the term "display frame" means a single screen-size image made up of a matrix of pixels which form a plurality of raster lines. A display frame is generally created by sequentially illuminating or refreshing the raster lines of the display device.
The UART of the Data-Link.TM. watch expects to receive data at a very specific bit rate of 2048 bits per second. This can be accomplished by correctly establishing the spacing of data transmission raster lines used on the display device for data transmission. More specifically, the spacing can be controlled by varying the number of unused raster lines between the data transmission raster lines which are selected to communicate data bits to the watch. The correct spacing, however, depends on the rate at which the display device scans or updates its pixels and raster lines. Not all display devices use the same scanning rate.
Initial development of the Data-Link.TM. watch was carried out on display devices operating at a screen refresh rate of 60 Hz (all pixels refreshed 60 times per second). A mammal calibration routine was developed for those users with "non-standard" display devices operating at different refresh rates. The manual calibration routine consisted essentially of repetitively transmitting a test character to the watch and manually increasing or decreasing the bit rate (corresponding to a respectively decreasing or increasing data transmission raster line spacing). This system is disclosed in U.S. patent application Ser. No. 08/251224 filed May 31, 1994, in the names of Brzezinski and Dvorachek and assigned to Timex Corporation. Two factors, however, combined to make this approach less useful. First, it was found that there a number of "non-standard" display devices in use, requiring some users to manually calibrate their systems. Second, it was found that the manual calibration routine was difficult to use. Errors would occur during calibration and users had difficulty identifying the sources of those errors. Many times, users had simply not yet learned where to hold the watch relative to the display device for optimum data reception. This led to confusion and an inability for many users to successfully calibrate their systems.